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dendrobates.org

Updates!

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After several years of dormancy, dendrobates.org has been updated. The current format allows for easier posting of blog-like updates, where the plan is to post about current research on poison dart frogs.

Although I have wanted to update the website for a long time, it wasn’t until I was contacted by Erik Melander that the project materialized. Erik generously offered to do a website redesign (more of a resurrection, really), while also offering to stay on as website administrator.

Since the last website updates, there have been a number of new species described. One of these, Excidobates condor (Almendariz et al. 2012), is remarkable in that it is the first entirely black poison dart frog. The authors also present larval data to suggest Andinobates abditus is actually a species of Excidobates. Following these results the genus Excidobates now contains three (likely four) species: E. mysteriosus, E. captivus, E. condor, and (likely) E. abditus.

Two new species of Andinobates have been described: The first of these Andinobates cassidyhornae (Amezquita et al. 2013) is a member of the bombetes group but differs from all other species phylogenetically and bioacoustically. Superficially, the species appears similar to A. opisthomelas.

The next new Andinobates is A. geminisae (Batista et al. 2014), which is a remarkable discovery in that the species occurs in a relatively well sampled area (north Panamanian coast, east of the Bocas del Toro). This species bears a striking resemblance to Oophaga pumilio but the two species are not closely related. Rather, Andinobates geminisae is closely related to A. minutus and A. claudiae.

Almendáriz, A., Ron, S. R., & Brito, J. (2012). Una especie nueva de rana venenosa de altura del género Excidobates (Dendrobatoidea: Dendrobatidae) de la Cordillera del Cóndor. Papéis Avulsos de Zoologia (São Paulo), 52(32), 387-399.

Amezquita, A., Marquez, R., Medina, R., Mejia-Vargas, D., Kahn, T. R., Suarez, G., & Mazariegos, L. (2013). A new species of Andean poison frog, Andinobates (Anura: Dendrobatidae), from the northwestern Andes of Colombia. Zootaxa, 3620, 163-178.

Batista, A., Jaramillo, C. A., Ponce, M. A. R. C. O. S., & Crawford, A. J. (2014). A new species of Andinobates (Amphibia: Anura: Dendrobatidae) from west central Panama. Zootaxa, 3866, 333-352.

Mimicry in Ranitomeya imitator

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Why does mimicry evolve?

Mimicry refers to shared warning coloration between co-occurring species. There are two main classes of mimicry: Batesian, and Müllerian. Batesian mimicry is when a non-toxic species resembles a toxic species. The benefits of Batesian mimicry are fairly obvious: by resembling a toxic species, a non-toxic species “tricks” a predator into thinking it is toxic, and thus avoids being attacked. Müllerian mimicry is when two (or more) toxic species share a common warning coloration. This spreads the cost of predator learning across a larger pool of individuals, reducing the per-capita mortality rate. In Müllerian mimicry, because both species are toxic and appear similar, a predator attacking species A will then avoid species B, and vise-versa. It is therefore a mutualistic relationship.

Slideshow 1 – Basics of Müllerian mimicry

An important point about Müllerian mimicry (and aposematic signals in general) is that they are positive-frequency dependent. This means they have “strength in numbers”: the more abundant a warning signal is, the greater protection it confers to those who possess it. This explains the elaborate mimicry rings in tropical butterflies, with numerous species “participating” by converging on a single wing pattern. This positive-frequency dependence also means that novel phenotypes that do not conform to the local mimicry ring will be at a disadvantage. Because these individuals are not recognized by predators as being toxic, they will be selectively attacked. This means that once a mimetic morph is established in an area, it will be stable and resistant to invasion by a foreign morph.

Mimicry in Ranitomeya imitator

In north-central Peru, the dendrobatid species Ranitomeya imitator bears a striking resemblance to other species of Ranitomeya (Figure 1).

 

figure-1-imitator-mimicry
Figure 1 – Mimicry in Ranitomeya imitator

These morphs occur in different geographical areas, forming a “mosaic” of mimetic morphs across the landscape (Figure 2).

figure-2-morph-distribution
Figure 2 – Distribution of mimetic morphs of R. imitator

The possibility of Müllerian mimicry in R. imitator was recognized by Rainer Schulte in the original description of the species (Schulte 1986). However, it was not rigorously tested till much later.

A key aspect of mimicry is that warning coloration is shared not by common ancestry, but by convergent evolution. In other words, if two species appear similar because they are very closely related, this is not mimicry but simply a symplesiomorphy (shared ancestral character). Symula et al. (2001) provided phylogenetic evidence that that color similarity between R. imitator and its co-mimics was not due to common ancestry, thus supporting the hypothesis of Müllerian mimicry. They found that all populations of R. imitator—despite their highly variable colorationwere members of a single, variable species, and that the co-mimic species were more distantly related. This meant that the color morphs found in R. imitator evolved after the split from its co-mimics, supporting the mimicry hypothesis.

Another important aspect of Müllerian mimicry is that co-mimics are (a) both toxic and (b) confer mutual protection on one another. In other words, a predator attacking species A will learn to avoid species B, and vise-versa. Surprisingly, these predictions were not tested in R. imitator until over a decade later, when Adam Stuckert published two papers on this topic. Alkaloid data confirmed that R. imitator was indeed toxic, possessing quantities of alkaloids comparable to (if not exceeding) that of the co-mimic species (Stuckert et al. 2014a). A predator-learning experiment further found that predators attacking the spotted morph of R. imitator learned to avoid attacking its co-mimic, the spotted morph of R. variabilis, and vise-versa (Stuckert et al. 2014b).

 

Mimicry as a cause of population divergence

While the evolution of mimicry causes phenotypic convergence among unrelated species, it can also drive phenotypic divergence within a species. If a species co-occurs with different potential model species, different mimetic morphs can be established in different geographical areas. Because these morphs are under local positive frequency-dependent selection, they are resistant to invasion by foreign morphs. This can lead to the formation of narrow transition zones between different mimetic morphs. In R. imitator, three such zones have been identified (Twomey et al. 2014, 2016).

Slideshow 2 – The establishment and spread of mimetic morphs and the formation of transition zones.

Mimetic transition zones are of considerable interest for evolutionary biologists as they yield insights as to how populations of a single species diverge and become reproductively isolated, which may give clues about how new species are formed. For example, transition zones that are very narrow indicate that there is strong selection against immigrant phenotypes crossing the zone (crossing either physically by dispersal, or “crossing” indirectly via morph hybridization). Morph-based assortative mating may also reinforce morph boundaries, leading to narrow transition zones. Ultimately, strong selection and assortative mating may reduce gene flow between morphs, leading to genetic structuring that coincides with the mimetic transition zone.

Slideshow 3 – Mimicry “transition zones” in Ranitomeya imitator.

In R. imitator, field work has led to the discovery of three mimetic transition zones: striped-banded, striped-spotted, and striped-varadero. These transition zones are characterized by narrow areas of rapid phenotypic change. For example, in the striped-banded transition zone, the Huallaga Canyon provides a “natural” transect: in the upper and lower areas of the canyon, pure banded and striped morphs are found, respectively. In the central areas, there is a shift from banded to striped phenotypes that occurs over a relatively short stretch of river (~5 km). In addition to the rapid color pattern shift, the central populations are much more phenotypically variable than the “parent” populations, consistent with the idea that these populations are mimetic hybrids.

In the case of the striped-banded transition zone, there is a shift in color pattern elements, specifically the dorsal coloration, dorsal pattern, and leg color/pattern. However, there is no evidence of assortative mating at the transition zone, and no evidence of a reduction in gene flow between morphs (Twomey et al. 2016).

The striped-spotted transition zone is similar in the sense that there is a shift in color pattern elements, but no evidence of reduced gene flow. This transition zone occurs at the lowland/highland transition north of Tarapoto, and tracks the variation seen in the polymorphic R. variabilis.

The striped-varadero transition zone is different in a few ways. First, it is much narrower than the other zones, approximately 2 km wide. Second, there is some evidence for assortative mating at the morph boundary, with the local striped morphs showing a preference for their own morph (Twomey et al. 2014). Third, there is relatively strong genetic structuring at the transition zone, indicating that the two morphs may be reproductively isolated. Finally, the two morphs are different in aspects seemingly unrelated to mimicry (but possibly related to reproduction): size (with the varadero morph being much larger), and calls (with the varadero morph having a lower, longer call). Because of the narrowness of the zone, the presence of assortative mating, and the reduction in gene flow, this zone may be indicative of an early, but incomplete stage of speciation that is being driven by Müllerian mimicry.

References

Schulte, R. 1986. Eine neue Dendrobates—art aus ostperu (Amphibia: Salienta: Dendrobatidae). Sauria 8:11–20.

Stuckert, A. M., R. A. Saporito, P. J. Venegas, and K. Summers. 2014a. Alkaloid defenses of co-mimics in a putative Müllerian mimetic radiation. BMC evolutionary biology 14:76.

Stuckert, A. M., P. J. Venegas, and K. Summers. 2014b. Experimental evidence for predator learning and Müllerian mimicry in Peruvian poison frogs (Ranitomeya, Dendrobatidae). Evolutionary ecology 28:413–426.

Symula, R., R. Schulte, and K. Summers. 2001. Molecular phylogenetic evidence for a mimetic radiation in Peruvian poison frogs supports a Müllerian mimicry hypothesis. Proceedings of the Royal Society of London. Series B: Biological Sciences 268:2415–2421.

Twomey, E., J. S. Vestergaard, and K. Summers. 2014. Reproductive isolation related to mimetic divergence in the poison frog Ranitomeya imitator. Nature Communications 5:1–8.

Twomey, E., J. S. Vestergaard, P. J. Venegas, and K. Summers. 2016. Mimetic divergence and the speciation continuum in the mimic poison frog Ranitomeya imitator. The American Naturalist 187:205–224.

Revision of Ranitomeya

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A summary of the taxonomic changes within Ranitomeya

October 2011 saw the publication of a monograph in Zootaxa entitled “A taxonomic revision of the Neotropical frog genus Ranitomeya (Amphibia: Dendrobatidae). This paper is the culmination of our (Jason Brown & Evan Twomey) field work done in Peru starting in 2004 and we feel that it is a substantial step forward in understanding the taxonomy of this confusing group of frogs. Here is a list of the taxonomically relevant info this paper contains:

  • A new genus, Andinobates, is described for most of the species previously contained in Minyobates.
  • A new species, Ranitomeya toraro, is described from Brazil.
  • Ranitomeya duellmani is synonymized with Ranitomeya ventrimaculata due to confusion surrounding the original type series of the latter species.
  • The definition of Ranitomeya variabilis is greatly expanded to include what was being referred to as R. ventrimaculata prior to this paper.
  • Phylogenetic and bioacoustic evidence suggests that Ranitomeya amazonica is indeed a valid species.
  • Ranitomeya lamasi and R. biolat are synonymized with R. sirensis.
  • Ranitomeya ignea and R. intermedia (which were recognized as full species by Grant et al. 2006) are placed back into synonymy with R. reticulata and R. imitator, respectively.
  • Ranitomeya rubrocephala is designated a nomen dubium and should be removed from species lists.

Other additions and contributions of the paper include: a) explicit definitions of species groups that reflect the current phylogeny, b) detailed distribution maps for all currently recognized species of Ranitomeya, c) tadpole descriptions for several species, d) summary of call data for many species, e) discussion of the current debate on whether or not to accept the Grant et al. (2006) taxonomy.

Many people seem to think taxonomists only make taxonomic changes so that they can keep their jobs. We can assure you that this is not the case. An accurate taxonomy is a critical foundation for any biological research. Many people who have the luxury of working on North American or European taxa take this for granted. Studies of biogeography, community ecology, evolution, etc. often use a species as an evolutionary unit. How could speciation research exist without an accurate assessment of species boundaries? Furthermore, as species are generally considered to be the ‘currency’ of conservation assessments, it is imperative that species are accurately defined if we are to make effective conservation decisions. Messy, old taxonomies only serve to promote confusion; the goal of our paper is to clean up some of the confusion that has surrounded the genus Ranitomeya. Below we discuss some of taxonomic changes which will be of interest to the general poison-frog enthusiast, and offer some explanations as to why these changes were made.

Description of Andinobates
The existence of two speciose, reciprocally monophyletic clades (two lineages that  evolved independently), within Ranitomeya has been recognized for decades. Myers (1987) acknowledged this diversity this when he described Minyobates to include the north-Andean, Chocoan, and Central American ‘diminutive’ species. Our current Andinobates is essentially identical to Myers’ Minyobates, except for M. steyermarki. One might ask: Why don’t we just use the name Minyobates to refer to these frogs, rather than erect a new name Andinobates? The reason is that the type species for Minyobates, M. steyermarki, belongs to a very different lineage than our current Andinobates. When molecular data became available in the early 2000s, it became clear that steyermarki was not closely related to the rest of the putative Minyobates species, and it has since been retained as a one-species genus. Nomenclatural rules dictate that the genus name must follow the type species wherever it goes (taxonomically speaking). Therefore, all the “old” Minyobates essentially had their name taken away, and by default became part of their most closely related genus (which for a while was Dendrobates and more recently became Ranitomeya).

Our description of Andinobates reflects the diversity which Myers recognized when he described Minyobates, and is thus in a sense a return to an older taxonomic arrangement. This also brings cohesiveness to the current definition of Ranitomeya. These two genera differ in several ways. First, they represent two very different biogeographical radiations, with Andinobates occupying the northern Andes of Colombia, the Choco, and lower Central America, whereas Ranitomeya is completely Amazonian. Second, there are good morphological characters which diagnose these genera: Ranitomeya can be diagnosed by the presence of pale limb reticulation (with a couple exceptions, particularly in mimetic forms of R. imitator), and Andinobates has 2nd and 3rd vertebrae fused. Now that we have sequence data for many species of Andinobates, we are confident this taxonomic arrangement is robust.

Synonymy of Ranitomeya duellmani and redefinition of Ranitomeya variabilis
This is one of the weirder and most unexpected outcomes of our revision. Here is a history of the scenario: The original type series of Ranitomeya ventrimaculata was collected from Sarayacu, Ecuador in the 1930s. There are actually two species present in Sarayacu: “duellmani” and “ventrimaculata“. The holotype of ventrimaculata was described as having parallel, pinkish dorsolateral stripes. Many years later, Schulte (1999) described Dendrobates duellmani from northern Peru. In fact, the species that Schulte (1999) described was the same species as the holotype Shreve used for his ventrimaculata. It is quite a confusing situation– but the bottom line is this: Shreve’s holotype of ventrimaculata was the same species as Schulte’s duellmani, thus, due to precedence, the name ventrimaculata is the valid name.

So what happens to everything that was referred to as ventrimaculata prior to this revision? This is another confusing matter and involves some more obscure taxonomic legislation. Originally, going into this project, we had planned to synonymize variabilis with ventrimaculata (in the old sense) as phylogenetic, morphological, and bioacoustic data suggests a single species. However, the name ventrimaculata, as mentioned above, had to be transferred to the frogs which were being called duellmani. This means there was a species which had its name taken away. As it turns out, the oldest available name for this species is variabilis. So, ironically, the name variabilis now gets applied far more broadly to everything that was previously considered ventrimaculata.

For the poison frog enthusiast, these changes can be summarized as follows:

  • Everything that used to be called duellmani is now called ventrimaculata
  • Everything that used to be called ventrimaculata is now called variabilis
  • Everything that was called variabilis is still called variabilis

Retention of Ranitomeya amazonica
Despite initial skepticism, Ranitomeya amazonica continues to receive support as a valid taxon. One of the main goals of this revision was to address the taxonomic issues surrounding R. variabilis (in the new sense) and its close allies (e.g. amazonica). It is clear that, when looking at results from phylogenetic analyses, there is a deep divergence between frogs associated with the Amazon (Iquitos, Leticia, eastern South America) and frogs from the upper Amazon/east Andean versant. Although diagnostic characters for R. amazonica have remained elusive, we conducted a large-scale analysis of advertisement calls and found that differences do exist between these two clades. Therefore, on the basis of phylogenetic and acoustic data, there was no strong evidence to suggest that R. amazonica should be synonymized.

From a practical standpoint, as far as we can tell, all individuals that are orange or red (mostly from the vicinity of Iquitos) fall within the amazonica clade (e.g. “red vents” should be treated as a “line” of R. amazonica). Furthermore, all frogs from French Guianan origin also should be treated as R. amazonica. Interestingly, R. variabilis (sensu the current revision) and R. amazonica come into very close contact south of Iquitos, and may even be sympatric in some areas, such as the Rio Tigre. More research is needed to determine how species boundaries are maintained in these contact areas.

Ranitomeya lamasi and R. biolat both become R. sirensis
Ranitomeya sirensis has been considered one of the most enigmatic poison frogs since its description in the early 1990s. Its unusual color pattern, coupled with the fact that it occupies a remote and isolated mountain range, left many researchers wondering how it was related to other Ranitomeya species. In 2007, Jason Brown, Evan Twomey, Mark Pepper, and Manuel Sanchez were successful in finding topotypic material in the Cordillera El Sira. Needless to say, we were quite surprised when phylogenetic data came back that placed this species directly in the middle of R. lamasi, rendering the species paraphyletic (in molecular taxonomy, the basis for species are unique evolutionary lineages). In 2008, another expedition shed further light on this issue. In this trip, several individuals from both “species” were seen breeding together in the foothills of the Sira, and furthermore, some intermediate individuals were found (e.g., individuals that looked like sirensis but with faint, scattered black markings). Thus, there was strong behavioral evidence which corroborated our phylogenetic evidence: that lamasi and sirensis were actually the same species.

Additionally, extensive sampling of R. biolat has failed to provide evidence that it is a distinct species from R. lamasi, with many putative biolat individuals interspersed throughout the lamasi clade. Although there are instances where gene trees and species trees may not coincide, in this case we had no reason to suspect multiple species were involved (mostly on the basis of similarity in morphology and advertisement calls). Thus, all our data suggested that biolat, lamasi, and sirensis all belonged to a single, widespread, polymorphic species.

Due to taxonomic rules, when this sort of thing happens, the name which came first is the valid name. In this case, sirensis was described first (Aichinger 1991), coming one year prior to Morales’ (1992) description of biolat and lamasi. Thus sirensis becomes the valid name. It is ironic that sirensis, which was previously thought to be one of the rarest and most enigmatic poison frogs, is now one of the most widespread and polymorphic species known.

For hobbyists, this change is simple: everything that was previously called lamasi is now sirensis.

Two new species of Ranitomeya from Peru – R. cyanovittata and R. yavaricola

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Two new species of Ranitomeya have been described from Peru: R. cyanovittata and R. yavaricola. Both species are members of the vanzolinii genetic group and both are known only from eastern Peru along the Brazilian border.

Perez-Pena, P. E., Chavez, G., Twomey, E., & Brown, J. L. (2010). Two new species of Ranitomeya (Anura: Dendrobatidae) from eastern Amazonian Peru. Zootaxa, 2439, 1-23.

New species of Ranitomeya from Amazonian Colombia

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A new species, Ranitomeya defleri, has been described from southeastern Colombia. The species is sister to an undescribed species from Brazil. It is sympatric with R. variabilis and appears to breed in phytotelmata such as bromeliads and tree holes.

Twomey, E., & Brown, J. L. (2009). Another new species of Ranitomeya (Anura: Dendrobatidae) from Amazonian Colombia. Zootaxa, 2302, 48-60.

Three new species of Ameerega from Peru – A. ignipedis, A. pepperi, and A. yoshina

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A recent paper in Zootaxa (Brown & Twomey 2009) describes three new species of Ameerega from Peru. Two of these species (A. ignipedis and A. yoshina) were discovered in the Serrania de Contamana, a poorly explored mountain range that is disjunct from the Andean foothills.

Brown, J. L., & Twomey, E. (2009). Complicated histories: three new species of poison frogs of the genus Ameerega (Anura: Dendrobatidae) from north-central Peru. Zootaxa, 2049, 1-38.

Rediscovery of Dendrobates captivus

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Spotted Poison Frogs: Dendrobates captivus expedition, Rio Santiago, 2006

Part one: In pursuit of the Pongo

Background

In 1924, geologist Harvey Bassler collected a small frog from the confluence of the Río Santiago and Río Marañón in northwestern Peru. Five years later, after collecting a bizarre frog from the Cordillera del Condor, Bassler collected two more frogs from the Santiago-Marañón junction on his way down the Marañón in a dugout canoe. These specimens were forgotten until being found in a museum collection in 1975, but it wasn’t until Charles Myers’ 1982 paper that these specimens were regarded as distinct species, naming the Cordillera del Condor species Dendrobates mysteriosus and the species from the Santiago D. captivus. Unfortunately, Bassler left no descriptions of live animals, leaving Myers only damaged specimens that had been in alcohol since the start of the Great Depression.

Rainer Schulte traced Bassler’s footsteps to the Cordillera del Condor, and in 1989 documented the first live Dendrobates mysteriosus. However, no such expeditions were ever attempted to rediscover Dendrobates captivus, and understandably so. The type locality as described by Bassler is located in an extremely remote area of Peru, accessible by following the Rio Marañón several days in a boat, only to be greeted by the infamous Pongo de Manseriche. This pongo, or rapid, is formed by a precipitous gorge that cuts through the Cerros de Campanquis, restricting the 750 meter-wide Marañón to a violent 120 meter-wide maelstrom. The peril of reaching the site is exacerbated its inhabitants, the Aguarunas, a sub-tribe of the Shuar Indians, who are most well-known for their curious practice of shrinking the heads of their enemies. These natives have a notorious reputation in Peru of being both fearful and aggressive towards foreigners, especially white ones, who they view as pishtacos (assassins whose primary objective is to extract fats from the bodies of their victims).

The secluded and dangerous nature of the Santiago valley has consequently made it one of the most poorly investigated areas of Peru. Very few biological investigations have been made in the area, and no herpetological surveys, aside from Bassler’s collection of D. captivus, had ever been attempted. For this reason, we decided to go, attempting to find a poison frog that hadn’t been seen by any scientist in 77 years. The expedition was conceived and planned by myself (Evan Twomey), Justin Yeager, Jason Brown, and Manuel Miranda (our contact with the Aguarunas). We were accompanied by Wouter Olthof (a Dutch student), and a small group of filmmakers (Collin Kettell and Richard Sines), an agronomist, and two Peruvian field-hands.

Day 1

Tarapoto – It is night, our truck is packed to the gills with people and supplies. In total there are ten of us leaving from Tarapoto, with the final destination of Rio Santiago, type locality for the elusive Dendrobates captivus. Tonight our only destination is Yurimaguas, a thriving port-town 4 hours north by road, but recent road-assaults have us all on edge. Despite the kidney-busting condition of the road, our excitement levels are through the roof, even though we are a long ways from our final destination. In Yurimaguas we hope to get a boat that will take us the rest of the way, two full days, by river.

Day 2

Yurimaguas – Getting up at 5 am was never so easy. Even though we didn’t get in until midnight, and had to spend the rest of the day on the boat, everyone jumped out of bed, anxious to make progress towards our final destination. Today is San Juan, the biggest holiday of the year for people living in Amazonian Peru. The preferred food on this day is a juane, a delicious but somewhat frightening tamale consisting of rice, hen, and egg, all wrapped in a leaf, so we bought a sack of them for the long ride ahead. Our plan of action was to descend the Rio Huallaga until the junction of the Marañón, whereupon we would make a westward turn to approach the Pongo de Manseriche from the east. After a long morning in the boat, we finally made it to the confluence of the Huallaga and the Marañón. The Rio Marañón is the primary headwater of the Amazon river, flowing briskly away from the Andes, and finally slugging its way across the lowlands to pick up the Rio Huallaga, and finally the Rio Ucayali, where the Amazon officially begins. From this point on, we would be fighting the current, so our progress would be substantially slowed. By nightfall, we only made it as far as San Lorenzo, a bustling town near the mouth of the Rio Pastaza. Here we replenished our enthusiasm with some more juanes and beer.

Day 3

San Lorenzo – Another day in the boat was ahead of us, but the possibility that we might make it in the field today had everybody anxious to get going. After fueling up, we continued our ascent of the Marañón. Before long, a chain of mountains rose out of the horizon: we were looking at the Cerros de Campanquis, the Andean front-range that effectively isolates the Santiago valley from the rest of Amazonia. By lunchtime we had made it to Sarameriza, an isolated but lively town a few hours downriver of the Pongo de Manseriche. After Sarameriza there were no more towns with gas stations, so we had to carry enough gasoline to last our boat for the next four days. Our boat driver had a change of heart – he did not now feel comfortable navigating the Pongo de Manseriche, having only done it once, several years back. Being in a town so close to the Pongo, we were able to find a young man with extensive experience navigating the area, being comfortable with both the Pongo de Manseriche and the natives living above it. After leaving Sarameriza and continuing up the Marañón, the excitement in the boat reached an all-time high. The Cerros de Campanquis rose higher and higher above the horizon, until they appeared as a massive green wall of virgin rainforest. By mid-afternoon, we had reached the tiny village of Borja, an old missionary station situated immediately under the shadow of the Pongo de Manseriche. This would be our last stop before the Pongo and our last stop before entering Aguaruna territory.

As we left Borja and made our way to the mouth of the Pongo, we realized that the peaceful lower Marañón had finally given way to a monster: a narrow canyon with powerful currents, whirlpools, and huge rocks. We were finally in a position to see the bottom of the Pongo de Manseriche, and it looked like someone had taken a huge axe and smashed the Cerros de Campanquis, leaving only a small sliver for a pass. To navigate the Pongo, one must pass through two treacherous straits, the first being where the Marañón smashes into a massive crag, forming an enormous maelstrom, locally known as the huaccanqui (literally, “you’ll cry” in Aguaruna). Passing this strait, one is then faced with a second, more perilous section know as the asnahuaccanqui (“you’ll cry until you rot”), a 100-meter stretch of whitewater riddled with boulders and whirlpools. As we made our way slowly and carefully up the Pongo, it felt like we were entering another world. The rocks were filled with strange birds (reminiscent of blue-footed boobies) and orchids, and long strands of moss hung from the trees and cliffs due to the constantly misty conditions inside the gorge.

When we asked our guide where we were going to camp, we thought he was joking when he told us we would make base camp inside the Pongo itself. However, after making it through the roughest spots, we were pleased to find a beautiful sand beach, surrounded by cliffs and mountains, the Marañón roaring past. Stopping here, we quickly unloaded the boat – there was still the chance at getting in the field for maybe an hour.

After only a few minutes in the forest, we spotted a small red frog on the forest floor, which Justin Yeager, having experience with Ecuadorian frogs, identified as Epipedobates parvulus. Further searching turned up more of this species, but the limited daylight cut short our search. The search for Dendrobates captivus would have to wait until tomorrow.

Meanwhile, our guide Manuel Miranda, along with an Aguaruna translator, were above the Pongo negotiating with the Aguarunas for us to enter their land the following morning. They returned later that night, several hours later than anyone anticipated. When we asked how negotiations went with the Aguarunas; a somber Manuel replied “Not good.”

Part two: Frogs and Indians

Day 4

Aguaruna village – We are sitting in a small thatched hut, surrounded by roughly 60 people from the Aguaruna tribe. The town leader has called a meeting to have a community discussion of our business there, and whether or not we should be allowed to enter their land will depend on their decision. Being surrounded by an entire village of wary natives is not a feeling any of us are soon going to forget. Many times, the discussions, which were conducted entirely in the Aguaruna language, would rise to turmoil, and people began to shout and point at us. We could see in the eyes of our translator that negotiations were not going well; no word-for-word translation was needed. Below is an excerpt from Jason Brown’s journal entry of the meeting with the Aguarunas:

“An hour after of entering the Aguarunas’ village, people began to yell and scream in Aguaruna. Everyone in our party’s skin turned a light shade of green, as we could tell things were not as controlled as we had hoped. Moments later, people began to clap and yell; this caused others to stand and yell. Everyone in our party looked on in terrified silence; fortunately after ten minutes, the chaos was subdued by a few elder Aguarunas when they forced 3 or 4 drunks to leave that had been getting aggressive. What exactly happened in those minutes, we will never know. One of the translators told us that one of the Indians stood up and proposed that they kill us, however few people responded. To muster support he began to clap, however this enraged many of the other Aguarunas whom violently opposed this proposal (which was good for us, but this is when we started to get scared). Again, we will never know what was said, but whatever was said was taken very seriously by all the members of the tribe and everyone voiced their opinion. This was one of the most terrifying moments of my life.”

Fortunately, our guides were able to calm the villagers down, and after much negotiating, the Aguarunas had agreed to let us in. We were assigned two guides for the rest of the day. As we hiked into their forest, we asked them if they had seen a small frog with spots on the back. They said they had, but since no photos existed of this frog we had no idea if we were even describing the right frog.

The most unbelievable feeling in the world is to stand at the edge of an unexplored rainforest, not knowing what lies inside. Only a handful of scientists had ever entered this region, and to our knowledge we were the first herpetologists to have ever been here. Somewhere in this forest was a tiny frog that had not been seen in 77 years, and had never been documented in life. We began to search along a streambed; the habitat looked promising. Jason Brown and I split off from the group to search along a smaller creek, but before long, we heard Justin Yeager yelling in the distance, “Captivus! Captivus!”. Jason and I came barreling down the creek, bristling with excitement, to find Justin with our guides looking into a small bucket. Peering in, we screamed out in excitement: inside was a Dendrobates captivus, and it was more spectacular than any of us would have ever imagined. This first frog was caught by one of our guides, who showed it to Justin. Immediately he realized what it was; a small poison frog with bright red spots on the back, so he called us down.

The following few hours were exhilarating. D. captivus were quite common. We were able to record their calls, observe courting behavior and tadpole transport, and document color and pattern variation. Our Aguaruna guides were amused. Here was a group of foreigners that had traveled several hundred miles to find a tiny frog, a frog which the natives had all seen many times before when hunting in the forest.

Later that afternoon we returned to the Aguaruna village for lunch, and eventually returned to our base camp, everyone satisfied and relieved that the expedition was a success. But we still had a lot of work to do. The Santiago river remained unexplored, as did the Cerros de Campanquis to the east. But tonight we celebrated the rediscovery of Dendrobates captivus, and slept contentedly in our hammocks.

Day 5

Rio Santiago – As we ascended the Santiago, the morning sky looked ominous. Our goal for the day was to try to document more populations of D. captivus along both sides of the Santiago, but it looked like our search would be compromised by the rain, which was now falling in sheets. This area posed no threat to us; we were now in the territory of the Huambisas, a rival tribe of the Aguarunas. Fortunately, the Huambisas were friendly and accommodating, and only had an interest in fighting other Aguarunas, usually over women or land. In fact, one of the Huambisa villagers informed us that there had been wars between the two tribes as recently as a couple years ago, but the Peruvian government had now been intervening to stop intertribal combat.

We spent much of the day inside a Huambisa house, learning of their culture and way of life. We were offered masato, a drink made from cassava which has been chewed by the Huambisa women and spat into a vessel to ferment. For the natives, this drink is a fundamental source of nutrition, and since refusal would be insulting, we reluctantly tasted it. As we sat with the Huambisas, looking at the nearby mountains, we realized that we had to cross them. To our knowledge, no scientist had ever been in these mountains: the potential for new discoveries was high. We asked our host if it was possible to cross the Cerros de Campanquis on foot; he informed us that it was, but few people made that trek anymore since the trails were very poor and it was easy to get lost. He did, however, suggest two guides, both of whom claimed to have walked the trail recently. According to them, it would take less than half a day to reach Borja. Our plan was set. We would set out early the next morning and try to traverse the Cerros de Campanquis.

Day 6

Base camp – The rain continued all night, dripping into our hammocks, making it difficult to sleep. When we informed our party of the plan to cross the mountains, few wanted to join us. Only a small group of us (Jason, Wouter, and I) had the desire to attempt this hike. The rest of our party would spend the day searching around the Pongo, and planned to meet us in Borja later that afternoon.

Since our guides told us the hike was possible to do in one day, we left behind our hammocks, bringing only some crackers and a water filter. Our plan was to leave from a village on the Santiago, striking east towards the mountains and Borja on the other side. Making our way across the Santiago plain to the mountains proved to be much more time consuming that anyone thought. The trails were worse than our guides remembered, and the rains from the day before had the rivers in flood stage. After a frustrating zigzag across multiple rivers, we made it finally to the base of the mountains, but it was already mid-afternoon. Ascending the mountains proved to be just as difficult. The small trail quickly narrowed to a game path, which had us perpetually hunched over to avoid the overhanging vegetation. Furthermore, frogs were nowhere to be found. Even Epipedobates parvulus, which was common in the lowlands, began to disappear around 500 meters elevation.

The forest on the top of the Cerros de Campanquis is entirely untouched by humans. Our guides now informed us that the last time anyone even set foot up here was 6 months ago, and that they had not walked this trail in over 20 years. The climb was slow, and we did not summit until 5 pm. Night was only 2 hours away, and we still had the entire descent in front of us. As we made our way down, the wet forest began to grow dark and cool. We quickly realized that there would be no way to make it out of the mountains before dark. Fortunately, we all had flashlights, so we continued to make our way down late into the night. The entire descent had us following the spine of a sheer ridge, and stumbling over strange volcanic rocks resembling jagged coral. Being on top of a ridge, water was nowhere to be found. We followed our guides for hours, frequently losing the trail, then backtracking, walking in circles, and the whole time in a direction that would lead us far to the north of Borja. Reaching town tonight was hopeless. Presently we had a bigger concern, which was water. We had not passed a stream since about an hour before the summit, and it was currently midnight.

Day 7

Cerros de Campanquis – Jason, Wouter, and I breathed a huge sigh of relief upon reaching a small stream, but after quenching our thirst, we came to the realization that we could go no further tonight. Our guides came to the same conclusion, so we found a dry spot on the forest floor, covered it with large leaves, and lay down for the night. Sleeping on the forest floor with nothing but the clothes on your back is quite uncomfortable. There are a multitude of creatures waiting to chew on you – bees, ants, mosquitoes – but we just had to deal with them until it was light enough to proceed. We got about 45 minutes of sleep the entire night. Our guides, perhaps feeling guilty about misleading us, spent the entire night trying to find the trail again. Below is another excerpt from Jason’s journal:

“The bed was terrible. There were twigs and branches sticking in my back. Soon after lying down, some strange animal began to rustle and hiss in the tree tops. I have no clue what it was, but when it started I was glad to look over and see Wouter sleeping on his stomach, face in the dirt. The noise continued on and off throughout the night. Because we had been hiking all day we were covered in sweat and the insects loved it. I was covered with strange mosquitoes and ants. Sometime around 3:00AM my right eye grew warm and began to pus. By morning my eye was red and infected and was tearing profusely. Around 5:30 AM we all got up and began hiking again as the sun crawled over the horizon. Sometime in the night our guides found the correct trail.”

We still were in the mountains, but after a few hours more of perseverance, the trail began to widen. We slowly approached the lowlands, and the human influence was noticeable again. We ended up hiking to a village several kilometers down river of Borja, but fortunately a Peruvian with a boat offered to take us back upriver to rejoin our party.

The other members of our team were relieved to find us alive, albeit exhausted. Though we did not find any more D. captivus, we were glad to learn that the others found several. Lunch in Borja was delicious and miraculously they had cold beer, which brought our vitality back in no time. Dendrobates captivus found, our mission was a success. After resting a bit, we all agreed it was time to make our way down the Marañón, back home.

Day 8

San Lorenzo – What a great town. We finally got to shower for the first time on the trip. Plus, San Lorenzo has some great food and even a pool hall. We decided to spend the day around San Lorenzo, getting into the field a bit on both sides of the Marañón, but didn’t find much. Dinner was cheerful and everyone appreciated a solid night’s rest.

Day 9

San Lorenzo – Today we were hoping to make it back to Tarapoto. We left San Lorenzo early, and after an entire day in the boat, made it to Yurimaguas by dinner time. After a long drive along some terrible roads, we finally made it back to Tarapoto, glad to be back safely.

Summary

The expedition was better than anyone would have predicted. Not only did we all make it out safely, but Dendrobates captivus turned out to be a little gem with some interesting behaviors. We thought this species might be brown with white or yellow spots, no one was predicting black with red spots and yellow flash marks. Overall, we surveyed several sites around the Pongo de Manseriche, and although there are undoubtedly more discoveries to be made there, we felt that this expedition was a good initial survey of an unknown area.

Though the Santiago valley is relatively undisturbed, nearby oil drilling and road construction may quickly place the area at risk for deforestation. We suspect that D. captivus may be restricted to the Santiago valley, and as such would have a very small range, thus being at elevated risk of habitat destruction or illegal collection for the pet trade.

-Evan Twomey
March 25th, 2007

holotypes
Holotypes of Dendrobates mysteriosus (left), and D. captivus (right). These specimens were collected by Bassler in the 1920s and were the only existing material for these species at the time of their description in 1982. (Myers 1982)

map
Map of the region. Our expedition followed the Marañón west to the mouth of the Rio Santiago.

pongo
Pongo de Manseriche, drawing from the late 1800s.

sunset
Sunset on road near Tarapoto. (Photo: Evan Twomey)

boat
Cramped boat for 2 days. (Photo: Jason Brown)

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Headwaters of the Amazon. (Photo: Wouter Olthof)

children
The children of Sarameriza wishing us well on our travels. (Photo: Jason Brown)

campanquis
Final approach of the Cerros de Campanquis. (Photo: Wouter Olthof)

manseriche
Entering the Pongo de Manseriche. (Photo: Wouter Olthof)

malpaso
Passing the asnahuaccanqui, most dangerous section of the Pongo de Manseriche. The driver made us get out and hike alongside for safety reasons. (Photo: Evan Twomey)

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A sight few have seen: the upper Pongo de Manseriche, June 26th, 2006. (Photo: Evan Twomey)

camp
Base camp in the Pongo. (Photo: Evan Twomey)

cooking
First night in camp. (Photo: Wouter Olthof)

boa
Rainbow boa (Epicrates cenchria) caught near camp. For most of us, this was the first wild rainbow boa we had ever seen. (Photo: Wouter Olthof)

upper_maranon
Rio Marañón above Pongo de Manseriche, near the mouth of the Rio Santiago. (Photo: Wouter Olthof)

captivus1
Dendrobates captivus, at last! Last seen in 1929, rediscovered in 2006. (Photo: Jason Brown)

captivus2
Photo: Evan Twomey

captivus3
Photo: Jason Brown

huambisa
Huambisa native, demonstrating to us his hunting technique. (Photo: Evan Twomey)

mantis
A peculiar leaf-mimic praying mantis, found near the Rio Santiago. (Photo: Jason Brown)

translation
Huambisa native, translating into Spanish for us. This was one of our guides on the crossing of the Cerros de Campanquis. (Photo: Richard Sines)

knee_deep
Crossing rivers on our way to the Cerros de Campanquis. This continued for half a day. (Photo: Jason Brown)

footprint
Footprints in the sand. On our approach to the Campanquis, we find very fresh jaguar footprints. This animal has become exceedingly rare in Peru over the past decade. (Photo: Evan Twomey)

bedtime
Bedtime in the Cerros de Campanquis. Wouter (left) and Evan (right) pay the penalty for packing light. (Photo: Jason Brown)

bromeliad
Waiting for a frog to come out of a huge bromeliad in the Cerros de Campanquis. (Photo: Wouter Olthof)

forest
Primeval rainforest, Cerros de Campanquis. (Photo: Jason Brown)

tree
Sunset, San Lorenzo. (Photo: Evan Twomey)

Rare Species for Sale! The Smuggling Crisis

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FOR SALE: Rarest Newest Species

It seems to be an inherently human characteristic to desire that which we do not have. Acquisition of a new species is one of the most exciting parts of this hobby. Every hobbyist has his or her own wish list, some of which are easily obtainable, others far more elusive. How these wish lists are filled can speak volumes about the integrity of the hobby and the individual hobbyists. The desire for new and rare species has directly fueled the exploitation of these frogs in the wild through a destructive practice known as smuggling.

What is smuggling?

With many amphibian species disappearing worldwide due to disease, global climate change, and deforestation, many conservation efforts have been spawned lately to investigate and combat such threats. However, poison frogs face a threat that has largely been overlooked – illegal smuggling for the pet trade. The last several years have witnessed recent waves of large volumes of smuggled frogs appearing at frog shows or expos, particularly in Europe, however N. America is far from innocent. Some species of particular note are Dendrobates mysteriosus, D. granuliferus, D. fantasticus, D. imitator, D. vanzolinii, many forms of D. lamasi (most recently the orange/red form), and D. lehmanni. The list is extensive, and continues to grow.

Smugglers exploit the often under-funded governing bodies and enforcement agencies in the countries in which these frogs are native. In Peru, smugglers either carry the frogs out of the country personally, usually several hundred at a time, hidden amongst luggage, or export the frogs illegally, hidden within shipments of tropical fish leaving through Iquitos or Lima. Many times large quantities of frogs are harvested from often very restricted populations, in most cases severely damaging these populations. Furthermore, impoverished Peruvian farmers are often paid ridiculously low sums of money ($1-2) to collect every poison frog they can find. Not only is this damaging to the frog populations, it instills in these farmers the idea that the forest and its inhabitants are just another resource to be carelessly exploited rather than conserved or managed sustainably.

These frogs, whether concealed in luggage or hidden with fish, are horribly and inhumanely packed, often resulting in the death of 100% of these illegal shipments. Seizure of illegal frogs in Iquitos revealed several film canisters packed with D. lamasi, often literally packed solid with frogs. The frogs face death as a result of the deplorable shipping conditions, or as the result of injuries received during the stress of such conditions, or from bacterial, fungal or viral infections which take over a weakened, stressed immune system. For every smuggled frog that arrives alive, there are many, many more that die. Customs officials have quoted mortality to be as high as 90%. Similar numbers have been observed within Peruvian seizures; sadly, one must be reminded that many more died before they could even be packed for transport.

Two months ago a new variant of D. imitator arrived Europe, recently we had the opportunity to return the area the frogs were from and see the impact. The site was dismal. Because the smugglers created a market for these frogs, half a dozen campensinos (farmers) had begun collecting the frogs and placing them in small enclosures. The mortality of the frogs waiting for export had to be considerably high as all the frogs we observed were severely starved and seemed to be barely alive. Further, a considerable amount of frogs which didn’t starve to death could have easily died of desiccation, excessive heat, predation, or disease, as many of the cages were so poorly built frogs could easily escape. However, if they were able to escape they were now miles away from suitable forests and surely died. Since the smugglers are stealing these frogs, to them, these losses are acceptable and they simply remove more from the wild. They will try again and again when mortality is high. To the campensinos, most of these frogs can be collected while they work in the forests, so the small chance that they live to be exported is still worth the effort. Smuggling has unfortunately become a highly lucrative venture benefiting only the smugglers themselves, as the short term income to the farmer hardly ameliorates their poverty.

How is it harmful?
Those who knowingly purchase illegal frogs are every bit as guilty as the smugglers themselves and by doing so are directly encouraging this trend to continue. There is no justification for these practices. No one wins, not the frogs, not conservation, not the hobby, and certainly not the local communities. Supporting these smugglers is directly supporting the extirpation of these frogs from the wild, and making it much more difficult for the sustainable projects to succeed.

No one can deny the clandestine origins of many of the now common frogs in the hobby, whose origins were smuggled animals. However, our hobby does not have to continue this way. Never in the history of the poison frog hobby have greater opportunities been available to the hobbyist to purchase a wide variety of sustainably produced frogs , which come with the additional benefit that portions of proceeds go to protect the very habitat these frogs come from. In many cases, supporting these projects aids the economies of impoverished local communities by providing them a sustainable source of income and employment opportunities derived from the forest, rather than from unsustainable exploitation.

Smuggling directly undercuts these programs. Projects such as INIBICO and Zoocriadero Exotics Frogs (UE) will not thrive if the market for these frogs is constantly filled by smuggled animals. These projects have significant overheads, operating costs, and support several employees. They will simply cease to function if they cannot make the sales they need, and disappearing with these projects would be the conservation potential these frogs have to offer.

What can be done?
Unfortunately, many hobbyists choose to ignore the possibility that frogs they are purchasing may be smuggled, or simply take on an apathetic “don’t ask, don’t tell” mentality, naively assuming that the frogs they are purchasing are of legal origin. We urge hobbyists to ask questions when buying any frog newly arriving on the market. It is a simple matter of asking the seller questions: Where are these frogs from? How were these frogs obtained? If they are captive bred, how were the parents obtained? Could you provide CITES documentation? Any legal seller should have quick answers to these questions and will be able to provide documentation for the frogs they are selling.

– Mark Pepper, Jason Brown, and Evan Twomey
January 15th, 2007

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